package ie.dcu.spca.view.product;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.view.LayoutInflater;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageView;
import android.widget.TextView;
import android.net.Uri;

import ie.dcu.spca.data.BasicDataManager;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * An easy adapter to map static data to views defined in an XML file. You can
 * specify the data backing the list as an ArrayList of Maps. Each entry in the
 * ArrayList corresponds to one row in the list. The Maps contain the data for
 * each row. You also specify an XML file that defines the views used to display
 * the row, and a mapping from keys in the Map to specific views.
 * 
 * Binding data to views occurs in two phases. First, if a
 * {@link android.widget.SimpleAdapter.ViewBinder} is available,
 * {@link ViewBinder#setViewValue(android.view.View, Object, String)} is
 * invoked. If the returned value is true, binding has occured. If the returned
 * value is false and the view to bind is a TextView,
 * {@link #setViewText(TextView, String)} is invoked. If the returned value is
 * false and the view to bind is an ImageView,
 * {@link #setViewImage(ImageView, int)} or
 * {@link #setViewImage(ImageView, String)} is invoked. If no appropriate
 * binding can be found, an {@link IllegalStateException} is thrown.
 */
public class IdNameBarcodePriceAdapter extends BaseAdapter implements
        Filterable {
    private int[] mTo;
    private String[] mFrom;
    private ViewBinder mViewBinder;

    private List<? extends Map<String, ?>> mData;

    private int mResource;
    private int mDropDownResource;
    private LayoutInflater mInflater;

    private SimpleFilter mFilter;
    private ArrayList<Map<String, ?>> mUnfilteredData;

    /**
     * Constructor
     * 
     * @param context
     *            The context where the View associated with this SimpleAdapter
     *            is running
     * @param data
     *            A List of Maps. Each entry in the List corresponds to one row
     *            in the list. The Maps contain the data for each row, and
     *            should include all the entries specified in "from"
     * @param resource
     *            Resource identifier of a view layout that defines the views
     *            for this list item. The layout file should include at least
     *            those named views defined in "to"
     * @param from
     *            A list of column names that will be added to the Map
     *            associated with each item.
     * @param to
     *            The views that should display column in the "from" parameter.
     *            These should all be TextViews. The first N views in this list
     *            are given the values of the first N columns in the from
     *            parameter.
     */
    public IdNameBarcodePriceAdapter(Context context,
            List<? extends Map<String, ?>> data, int resource, String[] from,
            int[] to) {
        mData = data;
        mResource = mDropDownResource = resource;
        mFrom = from;
        mTo = to;
        mInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    /**
     * @see android.widget.Adapter#getCount()
     */
    public int getCount() {
        return mData.size();
    }

    /**
     * @see android.widget.Adapter#getItem(int)
     */
    public Object getItem(int position) {
        return mData.get(position);
    }

    /**
     * @see android.widget.Adapter#getItemId(int)
     */
    public long getItemId(int position) {
        return position;
    }

    /**
     * @see android.widget.Adapter#getView(int, View, ViewGroup)
     */
    public View getView(int position, View convertView, ViewGroup parent) {
        return createViewFromResource(position, convertView, parent, mResource);
    }

    private View createViewFromResource(int position, View convertView,
            ViewGroup parent, int resource) {
        View v;
        if (convertView == null) {
            v = mInflater.inflate(resource, parent, false);
        } else {
            v = convertView;
        }
        bindView(position, v);
        return v;
    }

    /**
     * <p>
     * Sets the layout resource to create the drop down views.
     * </p>
     * 
     * @param resource
     *            the layout resource defining the drop down views
     * @see #getDropDownView(int, android.view.View, android.view.ViewGroup)
     */
    public void setDropDownViewResource(int resource) {
        this.mDropDownResource = resource;
    }

    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        return createViewFromResource(position, convertView, parent,
                mDropDownResource);
    }

    private void bindView(int position, View view) {
        final Map dataSet = mData.get(position);
        if (dataSet == null) {
            return;
        }

        final String[] from = mFrom;
        final int[] to = mTo;
        final int len = to.length;

        for (int i = 0; i < len; i++) {
            final View v = view.findViewById(to[i]);
            if (v != null) {
                final Object data = dataSet.get(from[i]);
                String text = data == null ? "" : data.toString();
                if (text == null) {
                    text = "";
                }

                boolean bound = false;
                if (mViewBinder != null) {
                    bound = mViewBinder.setViewValue(v, data, text);
                }

                if (!bound) {
                    if (v instanceof TextView) {
                        setViewText((TextView) v, text);
                    } else if (v instanceof ImageView) {
                        if (data instanceof Integer) {
                            setViewImage((ImageView) v, (Integer) data);
                        } else {
                            setViewImage((ImageView) v, text);
                        }
                    } else {
                        throw new IllegalStateException(
                                v.getClass().getName()
                                        + " is not a "
                                        + " view that can be bounds by this SimpleAdapter");
                    }
                }
            }
        }
    }

    /**
     * Returns the {@link ViewBinder} used to bind data to views.
     * 
     * @return a ViewBinder or null if the binder does not exist
     * 
     * @see #setViewBinder(android.widget.SimpleAdapter.ViewBinder)
     */
    public ViewBinder getViewBinder() {
        return mViewBinder;
    }

    /**
     * Sets the binder used to bind data to views.
     * 
     * @param viewBinder
     *            the binder used to bind data to views, can be null to remove
     *            the existing binder
     * 
     * @see #getViewBinder()
     */
    public void setViewBinder(ViewBinder viewBinder) {
        mViewBinder = viewBinder;
    }

    /**
     * Called by bindView() to set the image for an ImageView but only if there
     * is no existing ViewBinder or if the existing ViewBinder cannot handle
     * binding to an ImageView.
     * 
     * This method is called instead of {@link #setViewImage(ImageView, String)}
     * if the supplied data is an int or Integer.
     * 
     * @param v
     *            ImageView to receive an image
     * @param value
     *            the value retrieved from the data set
     * 
     * @see #setViewImage(ImageView, String)
     */
    public void setViewImage(ImageView v, int value) {
        v.setImageResource(value);
    }

    /**
     * Called by bindView() to set the image for an ImageView but only if there
     * is no existing ViewBinder or if the existing ViewBinder cannot handle
     * binding to an ImageView.
     * 
     * By default, the value will be treated as an image resource. If the value
     * cannot be used as an image resource, the value is used as an image Uri.
     * 
     * This method is called instead of {@link #setViewImage(ImageView, int)} if
     * the supplied data is not an int or Integer.
     * 
     * @param v
     *            ImageView to receive an image
     * @param value
     *            the value retrieved from the data set
     * 
     * @see #setViewImage(ImageView, int)
     */
    public void setViewImage(ImageView v, String value) {
        try {
            v.setImageResource(Integer.parseInt(value));
        } catch (NumberFormatException nfe) {
            v.setImageURI(Uri.parse(value));
        }
    }

    /**
     * Called by bindView() to set the text for a TextView but only if there is
     * no existing ViewBinder or if the existing ViewBinder cannot handle
     * binding to an TextView.
     * 
     * @param v
     *            TextView to receive text
     * @param text
     *            the text to be set for the TextView
     */
    public void setViewText(TextView v, String text) {
        v.setText(text);
    }

    public Filter getFilter() {
        if (mFilter == null) {
            mFilter = new SimpleFilter();
        }
        return mFilter;
    }

    /**
     * This class can be used by external clients of SimpleAdapter to bind
     * values to views.
     * 
     * You should use this class to bind values to views that are not directly
     * supported by SimpleAdapter or to change the way binding occurs for views
     * supported by SimpleAdapter.
     * 
     * @see SimpleAdapter#setViewImage(ImageView, int)
     * @see SimpleAdapter#setViewImage(ImageView, String)
     * @see SimpleAdapter#setViewText(TextView, String)
     */
    public static interface ViewBinder {
        /**
         * Binds the specified data to the specified view.
         * 
         * When binding is handled by this ViewBinder, this method must return
         * true. If this method returns false, SimpleAdapter will attempts to
         * handle the binding on its own.
         * 
         * @param view
         *            the view to bind the data to
         * @param data
         *            the data to bind to the view
         * @param textRepresentation
         *            a safe String representation of the supplied data: it is
         *            either the result of data.toString() or an empty String
         *            but it is never null
         * 
         * @return true if the data was bound to the view, false otherwise
         */
        boolean setViewValue(View view, Object data, String textRepresentation);
    }

    /**
     * <p>
     * An array filters constrains the content of the array adapter with a
     * prefix. Each item that does not start with the supplied prefix is removed
     * from the list.
     * </p>
     */
    private class SimpleFilter extends Filter {

        @Override
        public CharSequence convertResultToString(Object resultValue) {
            return (String) ((Map<String, Object>) resultValue)
                    .get(BasicDataManager.BARCODE);
        }

        @Override
        protected FilterResults performFiltering(CharSequence prefix) {
            FilterResults results = new FilterResults();

            if (mUnfilteredData == null) {
                mUnfilteredData = new ArrayList<Map<String, ?>>(mData);
            }

            if (prefix == null || prefix.length() == 0) {
                ArrayList<Map<String, ?>> list = mUnfilteredData;
                results.values = list;
                results.count = list.size();
            } else {
                String prefixString = prefix.toString().toLowerCase();

                ArrayList<Map<String, ?>> unfilteredValues = mUnfilteredData;
                int count = unfilteredValues.size();

                ArrayList<Map<String, ?>> newValues = new ArrayList<Map<String, ?>>(
                        count);

                for (int i = 0; i < count; i++) {
                    Map<String, ?> h = unfilteredValues.get(i);
                    if (h != null) {

                        int len = mTo.length;

                        for (int j = 0; j < len; j++) {
                            String str = (String) h.get(mFrom[j]);

                            String[] words = str.split(" ");
                            int wordCount = words.length;

                            for (int k = 0; k < wordCount; k++) {
                                String word = words[k].toLowerCase();
                                if (word.length() <= 0)
                                    continue;
                                if (word.startsWith(prefixString)
                                        || prefixString.startsWith(word)) {
                                    newValues.add(h);
                                    break;
                                }
                            }
                        }
                    }
                }

                results.values = newValues;
                results.count = newValues.size();
            }

            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint,
                FilterResults results) {
            // noinspection unchecked
            mData = (List<Map<String, ?>>) results.values;
            if (results.count > 0) {
                notifyDataSetChanged();
            } else {
                notifyDataSetInvalidated();
            }
        }
    }
}
